Crowding effects on the structural transitions in a flexible helical homopolymer

TL;DR

This study investigates how crowding agents influence the structural transitions of a flexible helical homopolymer, revealing that crowding induces chain compaction and affects helix stability depending on crowding conditions.

Contribution

It provides new insights into the effects of crowding on polymer structural transitions, specifically how crowding agents modulate helix formation and stability in off-lattice homopolymers.

Findings

Crowding induces chain compaction and promotes specific structural formations.

Helical content generally decreases with increased crowding.

Transition temperatures depend on crowding fraction, polymer length, and crowding particle size.

Abstract

We elucidate the structural transitions in a helical off-lattice homopolymer induced by crowding agents, as function of the number of monomers ($N$) and volume fraction ($\phi_c$) of crowding particles. At $\phi_c = 0$, the homopolymer undergoes transitions from a random coil to a helix, helical hairpin \textbf{HH}, and helix bundle \textbf{HB} structures depending on $N$, and temperature. Crowding induces chain compaction that can promote \textbf{HH} or \textbf{HB} formation depending on $\phi_c$. Typically, the helical content decreases which is reflected in the decrease in the transition temperatures that depend on $\phi_c$, $N$, and the size of the crowding particles.